Heating furnace for bands and wires



April 24, 1934. E, s 1,956,401

HEATING FURNACE FOR BANDSAND WIRES Filed June 18, 1932 2 Sheets-Sheet l17 If 11 1a 18 |10J I .9 1 I. 5 q\\\\\\\\\\\\\\\\ 12 6 II/ 0| H r I I 3|AI SecfomAA April 24, 1934. E FgRus 1,956,401

HEATING FURNACE FOR I BANDS AND WIRES Filed June 18. 1952 2sheets-shee't SQCZD'OnD-D Jam-(5;; c-c

Patented Apr. 24, 1934 PATENT OFFICE HEATING FURNACE FOR BANDS AND WIRESEmil Friedrich Russ, Cologne-on-the-Rhine,

Germany Application June 18, 1932, Serial No. 617,998 7 Claims. (01.263-3) This invention relates to heating furnaces for bands and wires,which are moved by means of transporting rollers through a tunnel-shapedfurnace heated by electric heating elements.

a rope.

An embodiment of the invention is illustrated by way of example in theaccompanying drawings in which:

Fig. 1 shows a furnace in longitudinal section. Fig. 2 is a crosssection of the furnace shown in Fig. 1, taken on line A-A.

Fig. 3 is a section taken on line BB of Fig. 1.

Fig. 4 is a part section taken as if on lines C-C of Fig. 3 but showingthe feed end of the latter furnace.

Fig. 5 is a part section on line DD of Fig. 3 showing the'discharge endof the latter furnace. In the drawings 1'] designates the straighttunnel-shaped channel, through which the wire 2 to be heated is moved inthe direction of the arrow 5 by means of conveyor rollers 3 and 4.Instead of bending the furnace in a catenary curve, the furnace isprovided near its centre with supporting rollers 6 and 7 covered withrefractory material, which rollers lie in vertical directionconsiderably lower than the conveyor rollers 3 and 4. Owing to thesesupporting r011 ers 6 and 7 the wire or band 2 is compelled to defectslightly from the curve which would exist in the event of free hanging.As the rope curve near the middle produces a very deep sag andconsequently just this portion of the rope curve is the cause of thedifficulty in the production of a curved furnace channeiin the knownfurnaces, it is possible, owing to the two supporting rollers 6 and 7,to employ the cheaper and more reliable furnace with straight centralaxis. As the supporting rollers 6 and '7 can be easily covered withrefractory material and bear only at a point against the material to beheated, scores and scratches on the band can easily be avoided, whichalways occur if the wires or bands are moved through the furnace spacein bearing on a plane surface. These known furnaces, in which it ispossible to produce a-straight line furnace tunnel with the aid ofnumerous supporting rollers in the furnace, are open .to the objectionthat the heat distribution on the band is not nearly as uniform as witha freely hanging band or wire.

A number of possibilities of adjustment are provided on the furnace inorder to avoid the difficulties which result from the changing of thesag curve, if the wire or band to be heated is of different material orhas other cross-section. The supporting rollers 6 and 7 are adjustable,

as shown in Fig. 3, in connection with the supporting roller 7. The axle31 of the supporting roller '7 is mounted outside the furnace. Thebearings 32 are fixed on iron plates 26, 27 which are bolted on thesheetmetal casing 3% of the furnace. A spindle 8 provided with a hand wheel10 is connected to each of the iron plates. The two apertures in themasonry at the insertion points of the supporting rollers are filledwith refractory bricks 35. The iron plates 26, 27 can be dismantled withthe bearings 32, the bricks 35 and supporting rollers withdrawn oradjusted into the desired position, as the iron plates 26 are providedwith slots and can therefore be screwed to any desired height. Thespindles 8 are attached to the iron plates 26, 27 as diagrammaticallysuggested in Fig. 1, and serve for effecting accurate horizontaladjustment. Consequently, it is possible, for example with constantconveying pull 5, to adjust the sag in the furnace so that the band orwire to be heated is situated at the correct distance from the heatingelements fixed on the Walls of the furnace channel. In a similarmannenthe conveyor rollers, which are situated outside the furnace, andalso the furnace doors 12 and 13 can be made so that they can be liftedand lowered, this being effected in the case of the doors by two pullropes 14 and 15, which are oscillatable through two-armed levers 16 and17 by handles 18 and 19, whereas the rollers are provided withadjustable bearings and clamping screws. By this adjusting device it ispossible, in a favorable manner, .to also lift the conveying rollers 3and 4 so that the sag of the material to be treated in the furnace isfavorable enough for a uniform heat- -to provide-the flanges of thefore-chambers 20 and 21 with slots so that the fore-chambers can beshifted as -desired relative to the end plates supporting rollers 6 and7 in the furnace 1 must wear considerably in spite of a refractorycovering of asbestos or the like, it is preferable to provide lateralapertures as shown in the region of the bearing blocks 26 and 27 in thefurnace body, which are closed by insulating plates to be screwedthereover in order to enable these supporting rollers 6 and l tobeeasily and rapidly exchanged.

As these supporting rollers 6 and 7 are further only loaded by a veryslight pressure from the wires 2, it being however difficult to makethese supporting rollers 6 and? easily rotatable, it is advisable tomechanically drivethese supporting rollers 6 and '7 at the same speed asthat at which the material 2 is conveyedlinearly in the direction ofmovement '5, in order to prevent slipping between the supporting-rollers 6 and 7 and the material 2. This mechanical drive of thesupporting rollers 6 and 7 may be effected in various manners, as can beimagined. The axles of the supporting rollers 6 and? may extendtransversely through the furnace and be rotated directly or indirectlyby a motor or by a gearing derived therefrom. It is also possible tointerconnect the axles of the supporting rollers 6 and 7, for example bymeans of a chain, so that only one supporting roller must be driven.

The arrangement and distribution of the heating elements in the channelof the furnace requires special care.,- If the construction of thechannel and the distribution of the heating elements is not carried outcorrectly, this is shown by the appearance of the bands heated'in thefurnace as soon as they leave the furnace. In this case they are bent orwarped. The latter phenomenon is particularly apparent when the heatingelements are arranged in the longitudinal direction of the furnacechannel. In the furnace according to the invention the'heating elementsare therefore arranged transversely to the axis of the furnace. Furthera larger number of heating elements are arranged on' the admission sideof the furnace, firstly in order to utilize the greater heat drop at theadmission point of the furnace and secondly in order to make it possibleto distribute the heat uniformly over the material over its entirewidth, and length when it is moving towards thedischarge end of thefurnace.

In order to enable a defective heating element 24 and 25 after looseningthe bolts 28. As the to be exchanged, if necessary whilst the furnace isin use, these elements can be so arranged that they can be removed fromthe furnace in lateral direction. The apertures for introducing andremoving the heating elements 30 are evidently made as narrow aspossible in order to prevent loss of heat.

I claim:-

1. In heating furnaces with rectilineal central I axis and conveyorrollers for the bands and wires situated outside the furnace, supportingrollers 3. In heating furnaces with supporting rollers covered withrefractory material in a generally centralregion of the furnace, furnacewallshaving lateral apertures within the range of movement of thesupporting rollers to allow the easy exchanging of the rollers.

4. In heating furnaces with supporting rollers situated in a generallycentral region of the furnace, mechanical drive for the supportingrollers to reliably prevent a slipping between the material to; beheated and the supporting rollers.

5. In heating furnaces with rectilineal longitudinal axis and conveyorrolls for conveying through the furnace material to be heated inotherwise freely hanging state, supports for the shafts of said rollers,and means connected therewith for a vertical shifting of the conveyorrollers.

6. In heating furnaces with vertically adjustable conveyor rollers, thecombination of adjustable conveyor roller carriers with the furnacedoors to permit of said doors being adjusted with said carriers.

'7. In heating furnaces. with rectilineal longitudinal axis and externalconveyor rollers and furnace doors adjustable in vertical direction,insulated extension chambers carrying the conveyor rollers and thefurnace doors as inclined flaps, and means for securing the sameselectively at different heights relative to the furnace body.

EMIL FRIEDRICH RUSS.

